image: Even small movements of hydrogen, shown in yellow, were found to cause large energy shifts in the attached iron atoms, shown in silver, which could be of interest in creating novel chemical reactions. view more
Credit: Jill Hemman/ORNL, U.S. Dept. of Energy
Neutrons uncover hydrogen’s hidden role in twisting iron
The positioning of hydrogen atoms was found to have a profound impact on the properties and dynamics of iron atoms that are important in many chemical reactions
Researchers from Yale University and Oak Ridge National Laboratory collaborated on neutron scattering experiments to study hydrogen atom locations and their effects on iron in a compound similar to those commonly used in industrial catalysts.
In the study, the researchers discovered that hydrogen atoms move around the core of the molecule rapidly, causing the energy levels of electrons in the attached iron atoms to shift dramatically. The speed of their movement was controlled by slight changes in the surroundings of the molecule, showing surprising sensitivity.
“This suggests that hydrogen can be used to tune the dynamics and the electronic structure of iron, which could be harnessed to create or improve chemical reactions,” said Patrick Holland, professor of chemistry at Yale.
Neutron diffraction experiments at ORNL’s Spallation Neutron Source were used to locate the precise positions of the hydrogen atoms. The data will also be useful for novel catalyst designs.
Media contact: Jeremy Rumsey, 865.574.2038, rumseyjp@ornl.gov
Satellites may enable better quantum networks
Entangled quantum particles are viable in space
A study by Oak Ridge National Laboratory researchers has demonstrated how satellites could enable more efficient, secure quantum networks.
“We used experiment, emulation and simulation to see what’s needed for high-dimensional quantum cryptography in space and found it’s quite doable,” said ORNL’s Joseph Chapman.
Quantum key distribution can use quantum bits, or qubits, to distribute shared random keys for users to exchange encrypted information. Qubits can exist in more than one state simultaneously and carry more information than standard computing bits. Qudits, another quantum unit, can exist in more than two states and carry even more information.
Chapman’s team used light particles to create entangled pairs of qubits and qudits, meaning one particle from a pair couldn’t be described independently of the other. The team emulated transmission between a ground station and satellite and simulated transmission from orbiting satellites.
“We found qubits and qudits are both viable,” Chapman said. — Matt Lakin
Media contact: Scott Jones, 865.241.6491, jonesg@ornl.gov
Reused car batteries rev up electric grid
ORNL innovation integrates old EV batteries into grid energy storage
When aging vehicle batteries lack the juice to power your car anymore, they may still hold energy. Yet it’s tough to find new uses for lithium-ion batteries with different makers, ages and sizes. A solution is urgently needed because battery recycling options are scarce.
Researchers at Oak Ridge National Laboratory have developed a new technology enabling battery reuse: a type of power electronics equipment that can manage a variety of EV batteries as an energy storage system for an electric utility. The mix of batteries can be controlled to release a predetermined amount of electricity to the grid. “We have each battery pack discharging at a different rate, while ensuring that the target energy output stays the same,” said ORNL’s Michael Starke.
When electricity demand spikes, utilities can use this stored energy instead of burning fossil fuels at “peaking” plants. The approach can reduce pollution, prolong the usefulness of EV batteries and make electricity service more reliable, at almost no cost.
Media contact: S. Heather Duncan, 478.718.9246, duncansh@ornl.gov
Pulling the shades for energy savings
Study shows honeycomb window coverings improve efficiency, reduce carbon emissions
Oak Ridge National Laboratory researchers demonstrated that window shades with a cellular or honeycomb structure provide higher energy savings during winter compared to generic venetian blinds and can save millions of tons of carbon emissions.
Windows contribute to energy demand in residential homes because they let heat escape; coverings can improve insulation. In a study, researchers compared the performance of three single-cell and two cell-in-cell-construction cellular shades with that of generic horizontal venetian blinds. The shades were installed from December to March for two heating seasons over windows in adjacent, identical second-floor rooms in a home in the Southeast United States.
“The room with the cellular shades achieved up to 24% heating energy savings,” ORNL’s Mahabir Bhandari said. Additional energy simulations predicted how the shades would perform in different climate zones. “Nationally, carbon emissions could potentially be reduced up to 3 million tons assuming a 20% penetration rate of cellular shades in residential buildings.”
Media contact: Jennifer Burke, 865.414.6835, burkejj@ornl.gov
Journal
Chemical Science